Sculptures entitled “The Rising Tide” by British sculptor Jason deCaires Taylor are seen beside the River Thames in front of the Houses of Parliament and the London Eye ferris wheel in London, September 3, 2015. The representations of four horses and riders are fully visible at low tide but become immersed underwater twice a day as the Thames rises to reach full tide. The installation will be on display throughout September as part of the annual Totally Thames festival. (Photo by Toby Melville/Reuters)

Astrid Perez (L) and Ramon Camacho lay on the Playa during the Burning Man 2015 “Carnival of Mirrors” arts and music festival in the Black Rock Desert of Nevada, September 6, 2015. Sunday marks the last day of the sold-out festival that gathered approximately 70,000 people from all over the world. (Photo by Jim Urquhart/Reuters)

A BASE jumper is pictured against the skyline shrouded in a thick haze during the Kuala Lumpur Tower International Jump in Kuala Lumpur, Malaysia, 02 October 2015. More than 100 BASE jumpers take part in this extreme sport event, which enters its 15th year. The haze hovering over Malaysia is caused by the ongoing plantation and forest fires in the nearby Indonesian provinces of Sumatra and Kalimantan. (Photo by Fazry Ismail/EPA)

Take a look at this stunning photo of Tolbachik, an active volcanic complex on the Kamchatka Peninsula in far eastern Russia. Lava fountains and rivers ran through the area for months after the eruption began with the opening of two Tolbachik fissures in November of 2012. In the midst of this activity, photographers Luda and Andrey (lusika33) took a trip down to see that stunning hell valley on earth. (Photo by lusika33)

U.S. players push head coach Adam Krikorian into the pool after they defeated the Netherlands in their women's water polo gold medal match during the Aquatics World Championships in Kazan, Russia, August 7, 2015. (Photo by Michael Dalder/Reuters)

People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

Children in Hiroshima, Japan, wearing masks to combat the odour of death after the city was destroyed by the first atom bomb. (Photo by Keystone/Getty Images). 1945

A donkey is seen before the start of the procession of the “Virgem da Atalaia” during Holy Week at Alcochete, near Lisbon April 5, 2015. Women ride donkeys during the “Virgem da Atalaia” procession, that has been held annually for about 400 years. In the past, only single women rode the donkeys to ask for help from the Virgin to find a husband. (Photo by Rafael Marchante/Reuters)